It is not too difficult. One good thing to do is study in detail how a professionally assembled bike has been put together. Look at everything: size and number of headset stack spacers, placement of brake cable guides, length of trimmed cables, bar wrapping. You will need a few tools: metric sockets and driver, hex wrenches, a good cable cutter, scratch awl for cable housings, chain whip, torque wrench, maybe a pin spanner (check the pin size first), adapters for tightening the cassette and bottom bracket, small bits like cable crimps, rubber cable protectors, cable housing ends, low-temp loctite and a good grade of machine grease. A third hand tool can be helpful in setting up brakes. A folding bike stand is useful, too. If you plan on fitting generic fenders, a Dremel and cutoff wheel is useful.
If you want to support the LBS, you could buy some tools there. You might also want them to press your headset for you, but there are postings here that show you how to do it yourself with about $10 worth of hardware parts.
Last edited by CHenry; 02-23-06 at 06:04 AM.